You're adding a lot of assumptions in order to reach that conclusion.
Generally it's not a good idea to reduce someone else's comment to a blunt denunciation, and especially not when you're adding a putdown of your own ("that is a LOT of words"). The commenter was obviously offering a complex expression of their experience and not just circomlocuting a crudity.
I assume you mean "you" here in the sense of "one" because I didn't say those other things. And certainly the "that is a lot of words" framing is something I personally dislike as well, but the conclusion seems accurate, doesn't it?
If German companies routinely have a glass ceiling for foreigners that they don't have for natives then surely in the American context we'd consider that bigotry of some sort and certainly if it were in the US we'd consider it a Title VII violation of the CRA on the basis of national origin.
I think it would help to provide an example by construction: relax one or more of the assumptions you think are being smuggled in and describe how it is not xenophobia to do what the German organizations OP was at were doing. I'm struggling to come up with something here - some kind of cultural mismatch not related to language fluency?
What it seems to me is that the OP, immigrant that he is, is describing a fairly xenophobic society that he nonetheless has to live in and is therefore not using explicit labels for.